When does Torchwood start again?

Took my 3yr old DD2 to Cardiff Bay last Saturday as it was such a lovely warm sunny day and we had our lunch sitting on the edge of the "hub".She enjoyed playing with the silver tower waterfall and got a bit wet.She then decided that she wanted to run down to the bay itself and i had to run after her.Felt like Captain Jack, running to catch the Tardis (sad ain't i ?)We then had a lovely trip around the bay to look at the barrage.All in all it was a lovely day.Oh, yeah just to get back to my question, when DOES the new series start?